I was out for a walk early Monday morning, dodging the few raindrops which insisted on attacking me, when I noticed something strange about the sidewalk. Or rather, I noticed the absence of something.
There were no earthworms to be seen on the sidewalk. When I went for a walk in the same area on Saturday, you could hardly take a step without having to be worried about stepping on a worm, but Monday – nothing.
I found that strange, given the worms’ propensity for slithering all over the sidewalks and streets after a rain.
It made the walk a little easier, considering after Saturday’s worm-dodging walk I had considered bringing a small twig with me to flip the worms back into the soil beside the paved areas and saving them from drying out when the sun showed up.
After I got home from my walk Monday (which by the way marked exactly seven months to Christmas), I decided to check out a few things about earthworms. I found a website from Ecowatch called “10 Interesting Facts About Earthworms” which, I have to admit, was about twice as many as I figured there would be.
Some of the facts were pretty straightforward, such as that earthworms actually come in about 6,000 species worldwide, and that in the tropics, some of them can grow to about 10 feet long. (I don’t think my little twig would help with moving one of those.)
What I found most interesting, though, was the article saying earthworms are not as good for the ecosystem, especially in Canada, as most people probably think. Turns out that the last Ice Age (which was not just last winter, despite that one bad cold spell) wiped out earthworms through Canada and into the northern United States. Well, it was actually the glaciers that wiped them out, but they came as a package deal with the Ice Age.
So where did all the worms we see in these parts come from? They’re imports, either accidentally in dirt brought from other areas, or intentionally, by farmers hoping to improve the soil through the use of worms.
And in some areas, the worms do improve the soil, mainly through the burrows they leave as they tunnel through the soil. This helps farmers, especially, but it turns out there is a flipside to the whole thing.
According to the Ecowatch article, the forests that showed up here after the glaciers retreated need a layer of decomposing material on top of the soil. Earthworms, it turns out, love that material, which means that when they get into our forests, they rob the trees of nutrients, as well as depriving a lot of species of insects of their living quarters.
The article doesn’t go so far as to say you should stomp on any earthworms you see on the street or sidewalk, but it does suggest ways to make sure they don’t spread into new ecosystems.
It’s amazing the stuff you learn staring at the ground as you walk.